sync: bring over remaining release/custom-0.1.115 changes

- Extract PublicSettingsInjectionPayload named struct with drift test
- Add channel_monitor_default_interval_seconds to SSR injection
- Add image_output_price to SupportedModelChip
- Simplify AppSidebar buildSelfNavItems (admins see available channels)
- Add gateway WARN logs for 503 no-available-accounts branches
- Wire ChannelMonitorRunner into provideCleanup for graceful shutdown
- Add migrations 130/131 (CC template userid fix + mimicry field cleanup)
- Clean up fork-only features (sora, claude max simulation, client affinity)
- Remove ~320 obsolete i18n keys
- Add codexUsage utility, WechatServiceButton, BulkEditAccountModal
- Tidy go.sum

backend/internal/service/ratelimit_session_window_test.go

@@ -73,6 +73,9 @@ func (m *sessionWindowMockRepo) GetByCRSAccountID(context.Context, string) (*Acc
 func (m *sessionWindowMockRepo) FindByExtraField(context.Context, string, any) ([]Account, error) {
 	panic("unexpected")
 }
+func (m *sessionWindowMockRepo) CountByTLSFingerprintProfile(context.Context) (map[int64]int, error) {
+	panic("unexpected")
+}
 func (m *sessionWindowMockRepo) ListCRSAccountIDs(context.Context) (map[string]int64, error) {
 	panic("unexpected")
 }